1. Field of the Invention
This invention relates to chain stitch sewing machines, and more particularly to an improvement in a mechanism where, in the chain stitch sewing machine which performs chain stitch sewing by cooperation of a needle that is driven to reciprocate in a vertical direction and a looper that is controlled for rotation in synchronization with the needle, thread changeover can be performed by selecting any desired one of a plurality of loopers.
2. Description of the Related Art
Chain stitch sewing machines, constructed so that thread changeover can be performed by selecting any desired one of a plurality of loopers, are disclosed, for example, in Japanese Patent Publication No. SHO 61-27075, Japanese Patent Publication No. HEI 1-53385, Japanese Unexamined Patent Publication No. HEI 5-239757, and Japanese Unexamined Patent Publication No. HEI 6-248560.
In any of the chain stitch sewing machines disclosed in the aforementioned publications, a drive mechanism for rotating and controlling a looper and a drive mechanism for selecting a desired looper from among a plurality of loopers are individually provided independent of each other. For this reason, the number of parts becomes increased as a whole, so that there is the drawback that a structure becomes complicated and a cost of production is increased.